0. Understanding and Preventing Amblyopia

1. Understanding Amblyopia
When the doctor sees nothing and the patient sees nothing, the diagnosis is ambluwpia.  Hippocrates, 450 BCE

2. AMBLYOPIA: DEFINITION
Understanding Amblyopia
AMBLYOPIA: DEFINITION
Abnormal visual development
Decreased best-corrected visual acuity
Unilateral or bilateral
Apparently normal physical exam, but may also result from recognizable structural abnormalities

3. AMBLYOPIA: SIGNIFICANCE
Understanding Amblyopia
AMBLYOPIA: SIGNIFICANCE
2%–4% of U.S. population affected
Commonly unilateral
Bilateral amblyopia (rare) may mean permanently decreased visual acuity

4. SCREENING: IMPORTANCE
Understanding Amblyopia
SCREENING: IMPORTANCE
Amblyopia is usually preventable or treatable
Early detection is key to effective treatment
Life-threatening disorders may present as amblyopia
Screening responsibility rests with primary care physician

5. In most circumstances, amplyopia can be prevented or treated.
Understanding Amblyopia
In most circumstances, amplyopia can be prevented or treated.

6. EARLY DETECTION: IMPORTANCE
Understanding Amblyopia
EARLY DETECTION: IMPORTANCE
Visual function develops early in life
Treatment depends on plasticity of visual system
Treatment less likely to be effective as children age

7. Decreased vision  retinoblastoma?
Understanding Amblyopia
Decreased vision  retinoblastoma?

8. Understanding Amblyopia
The ophthalmologist treats amblyopia, but the primary care physician detects amblyopia.

9. PREVENTING AMBLYOPIA: CONSIDERATIONS
Predisposing factors
Presenting features
Detection methods
Treatment rationale

10. AMBLYOPIA: PREDISPOSING FACTORS
Preventing Amblyopia
AMBLYOPIA: PREDISPOSING FACTORS
Poor clarity (media opacities) or blockage of light pathway (ptosis)
Poor focus (refractive error)
Poor aim (strabismus)

11. Preventing Amblyopia
Poor clarity

12. Preventing Amblyopia
Poor focus one eye

13. Preventing Amblyopia
Poor focus both eyes

14. Preventing Amblyopia
Poor aim: strabismus

15. UNILATERAL AMBLYOPIA: PRESENTATION
Preventing Amblyopia
UNILATERAL AMBLYOPIA: PRESENTATION
Failed vision test
Strabismus
Parental concern
Family history of amblyopia or strabismus

16. VISION SCREENING AGES 3-5
Preventing Amblyopia
VISION SCREENING AGES 3-5
May peek around occluder
Adhesive patch works best

17. Strabismus is the most common underlying cause of amblyopia.
Preventing Amblyopia
Strabismus is the most common underlying cause of amblyopia.

18. DIPLOPIA IN CHILDREN Not a feature of strabismus
Preventing Amblyopia
DIPLOPIA IN CHILDREN
Not a feature of strabismus
May indicate a serious condition
Evaluate promptly and refer

19. Preventing Amblyopia
PARENTAL CONCERNS
Leukocoria
Enlarged cornea

20. A positive family history is often present in children with amblyopia.
Preventing Amblyopia
A positive family history is often present in children with amblyopia.

21. Preventing Amblyopia
Bilateral amblyopia

22. AMBLYOPIA: EARLY DETECTION
Preventing Amblyopia
AMBLYOPIA: EARLY DETECTION
Assess red reflex
Determine visual acuity
Evaluate ocular alignment

23. Preventing Amblyopia
Normal red reflex

24. Preventing Amblyopia
Assymetric red reflex

25. Direct ophthalmoscope
Preventing Amblyopia
Direct ophthalmoscope

26. Direct ophthalmoscope: assessing red reflex
Preventing Amblyopia
Direct ophthalmoscope: assessing red reflex

27. Direct ophthalmoscope: examining retina
Preventing Amblyopia
Direct ophthalmoscope: examining retina

28. Preventing Amblyopia
Can your child see?

29. NORMAL INFANT VISION Good visual function
Preventing Amblyopia
NORMAL INFANT VISION
Good visual function
Fixate and follow with each eye
Steady fixation

30. Testing infant vision: Can your child see?
Preventing Amblyopia
Testing infant vision: Can your child see?

31. Suspected poor vision: test response to bright light
Preventing Amblyopia
Suspected poor vision: test response to bright light

32. Testing infant vision: Preferential looking test
Preventing Amblyopia
Testing infant vision: Preferential looking test

33. Measuring visual acuity at 18 months to 3 years: picture chart
Preventing Amblyopia
Measuring visual acuity at 18 months to 3 years: picture chart

34. Picture chart Single E chart
Preventing Amblyopia
Picture chart Single E chart

35. Preventing Amblyopia
Snellen acuity chart

36. Depth perception (stereopsis) testing
Preventing Amblyopia
Depth perception (stereopsis) testing

37. Testing infant vision: Assessing corneal light reflex
Preventing Amblyopia
Testing infant vision: Assessing corneal light reflex

38. Preventing Amblyopia
Normal
Esotropia

39. Preventing Amblyopia
Normal
Exotropia

40. Hypertropia Hypotropia
Preventing Amblyopia
Hypertropia
Hypotropia

41. Eyes appear aligned with head tilt and turn.
Preventing Amblyopia
Eyes appear aligned with head tilt and turn.
Misalignment revealed when head is straightened.

42. REFERRAL: IMMEDIATE Poor red reflex in one or both eyes
Preventing Amblyopia
REFERRAL: IMMEDIATE
Poor red reflex in one or both eyes
Concern about visual function by parent or doctor
Asymmetric or diminishing visual acuity
Constant or acute-onset strabismus

43. REFERRAL: LESS EMERGENT
Preventing Amblyopia
REFERRAL: LESS EMERGENT
Intermittent strabismus on examination
Persistent parental concern
Associated syndromes or systemic disease
Reduced visual acuity in one or both eyes

44. AMBLYOPIA: TREATMENT RATIONALE
Preventing Amblyopia
AMBLYOPIA: TREATMENT RATIONALE
Clearing the media
Focusing the image
Initiating amblyopia therapy

45. Preventing Amblyopia
Congenital cataracts

46. Preventing Amblyopia
Congenital ptosis

47. Ophthalmologists can quantify refractive error in infants.
Preventing Amblyopia
Ophthalmologists can quantify refractive error in infants.
Children usually do well with eyeglasses.

48. Carefully supervise children wearing therapeutic contact lenses.
Preventing Amblyopia
Carefully supervise children wearing therapeutic contact lenses.
Retain a pair of backup eyeglasses.

49. OCCLUSION THERAPY: PURPOSE
Preventing Amblyopia
OCCLUSION THERAPY: PURPOSE
Improves visual acuity
Does not eliminate strabismus

50. OCCLUSION THERAPY: PRECAUTIONS 1
Preventing Amblyopia
OCCLUSION THERAPY: PRECAUTIONS 1
Monitor visual acuity carefully at close intervals
Ensure vision is not being reduced in non-patched eye (“occlusion amblyopia”)

51. OCCLUSION THERAPY: PRECAUTIONS 2
Preventing Amblyopia
OCCLUSION THERAPY: PRECAUTIONS 2
Part-time occlusion may suffice
Ensure parents understand purpose of patching and importance of compliance
Follow child’s visual status into the teen years

52. Skin irritation from patching can be avoided.
Preventing Amblyopia
Skin irritation from patching can be avoided.

53. ATROPINE PENALIZATION THERAPY
Preventing Amblyopia
ATROPINE PENALIZATION THERAPY
Atropine ointment or drops in non-amblyopic eye at prescribed levels
Atropinized eye cannot accommodate for near vision
Child can still use better-seeing eye for distance
Child switches fixation at near to amblyopic eye

54. ATROPINE THERAPY: PRECAUTIONS
Preventing Amblyopia
ATROPINE THERAPY: PRECAUTIONS
Monitor VA carefully.
Ensure near VA in amblyopic eye can support near tasks
Allergic reactions are rare (<1%)
Systemic side effects are uncommon and minimal
Warn parents that one eye will
have a “fixed and dilated pupil.”

55. Medieval “occlusion masks” to treat strabismus and amblyopia
Preventing Amblyopia
Medieval “occlusion masks” to treat strabismus and amblyopia

56. AMBLYOPIA: PREDISPOSING FACTORS
Summary
AMBLYOPIA: PREDISPOSING FACTORS
Poor clarity of ocular media or light blockage
Poor focus
Poor aim

57. AMBLYOPIA DETECTION Assess red reflex Determine visual acuity
Summary
AMBLYOPIA DETECTION
Assess red reflex
Determine visual acuity
Evaluate ocular alignment

58. AMBLYOPIA TREATMENT Clearing the ocular media Focusing the image
Summary
AMBLYOPIA TREATMENT
Clearing the ocular media
Focusing the image
Amblyopia therapy
Success requires communication among parents, PCP, and ophthalmologist